Process for caramelizing sugar



March 8, 1966 3,239,379 HEINRICHJURGEN FREIHERR VON DRACHENFELS PROCESSFOR CARAMELIZING SUGAR FIG. I.

Original Filed Feb. 14, 1962 FIG. 2.

INVENTOR HEINRICH JURGEN vou DRACHENFELS United States Patent C)3,239,379 PROCESS FGR CARAMELIZING SUGAR Heinrich-Jurgen Freiherr vonDrachenfels, Hannover- Bothfeld, Germany, assignor to Werner Bahlsen,Hannover, Germany Original appiication Feb. 14, 1962, Ser. No. 173,219.Divided and this application July 20, 1964, Ser. No. 383,649 Claimspriority, application Germany, Feb. 17, 1961, B 61,335 3 Claims. (Cl.127-63) This is a division of copending application Serial No. 173,219,filed Feb. 14, 1962.

This invention relates to a method of oararnelizing sugar.

In the known devices for producing caramel sugar, in most cases thecrystalline sugar is caused to melt in a kettle consisting of metal. Inthis process the sugar is added in small portions in empiricallypredetermined time intervals. In carrying out said process the firstportion introduced into the kettle is allowed to melt to a certaindegree, then the next portion is introduced until this portion is alsomolten and so on. The mass is constantly kept in motion by means of astirrer introduced into the kettle.

In this manner-depending on the size of the container or kettleapredetermined amount of sugar can be melted and poured out, e.g., bytilting the kettle into pans in which it cools down and solidifies.

The blocks of caramelized sugar thus obtained are then in mostcasesdepending on their intended usebroken in pieces, ground or used assugar chips or fragments.

This process as well as similar processes have the following draw-back:

Due to its forced, gradual introduction, the mass which is introducedfirst, is kept, in comparison to the portion which is last introduced,consider-ably longer in a relatively high range of temperature and isdiscolored correspondingly stronger, because the color of molten massesof'sugar is very essentially dependent on the temperature of the massand the duration of the respective temperature. Therefore, theseconditions partially determine the total color tone of the mass.

It is not possible to obtain the molten sugar thus prepared intransparent condition because there are always tiny crystals in the masswhich were not affected by the melting process. The obtaining oftransparent molten sugar was hitherto possible only by melting smallamounts of sugar in containers of correspondingly small size.

Furthermore, it causes considerable difliculties to obtain the variouscharges of molten sugar with a uniform color, because the color isessentially dependent on the duration of melting and cannot be alwayskept constant. It is also a disadvantage that the known processes forproducing relatively large amounts of caramelized sugar, require verymuch space and they must be constantly manually fed, observed anddischarged. The heat energy consumption of such processes is very high.If it is desired to obtain a predetermined color, this can be done onlyby discharging the melting vessel in smaller pans in which thedischarged molten sugar cools down as quickly as possible. In order tosecure the obtaining of a specific color, extensive precautions arenecessary in order to melt and then cool down the mass withinpredetermined periods of time.

In contrast to these processes known from the art, according to thepresent invention the crystalline sugar is molten in a continuouslyoperated process in which the sugar passes through the device and isimmediately cooled and thereby by regulation of the temperature thedesired color can be obtained without difiiculty.

A particular advantage of the process according to the ice presentinvention in that the molten sugar remains transparent.

Due to the uniform condition of the mass a uniform taste is alsoassured.

The continuous process of the invention renders it possible to bring themolten sugar in the form of drops onto a cooled surface where thedeposited molten sugar drop solidifies immediately. Therefore, it is notnecessary to pour the caramelized sugar first into pans and comminute itsubsequently.

A further advantage consists in that the flowing molten sugar can beapplied in the form of a continuous film to a metal drum which may becooled or to a cooled band, on which it solidifies in the form of acontinuous molten band of sugar.

The appended drawings illustrate by way of example devices in which theprocess of the present invention can be carried out.

FIG. 1 shows a device for the continuous production of a continuousmolten film of sugar in section and in perspective;

FIG. 2 shows the same device, in which however, the discharge opening ofthe device is modified in order to form drops;

FIG. 3 shows a modified device for an increased melting capacity;

FIG. 4 is a section through a further device in nozzle shape;

FIG. 5 illustrates the use of the process according to the presentinvention for applying caramelized sugar in the form of strands to apiece of pastry in continuous operation.

In FIG. 1 the reference symbol 1 denotes oppositely arranged heatedplates, the distance of the plates being selected in such manner that agap a is formed into which the crystalline sugar can be fed from above.The crystalline sugar falls due to its own weight from the container 4in the funnel shaped recess 3. Thereby, the edges 5, 6 of the funnelshaped recess 3 extend so high that the sugar running out from container4 cannot be pressed beyond the edges 5 and 6.

The heated plates 1, 2 consist preferably of metal and are provided withbores 7, 8 etc. in which rod-formed electrical heating elements 9 areintroduced. Instead of the electrical heating elements 9 any othersuitable heating means, e.g., gas flames, can likewise be used. The onlyessential condition is that the plates 1, 2 be brought to the desiredtemperature in order to melt the crystalline sugar.

As crystalline sugar melts at about 200 C., the plates are brought to anessentially higher temperature which can be regulated.

Upon feeding the crystalline sugar into the gap a the crystalline sugarstarts to melt and continues to flow up to the discharge b of the gap.

During melting the individual molten parts flow together within the gapa so that at the outflow b a continuous film 10 of molten sugar isdischarged.

By the length of gap a and the temperature the period of passage of thematerial to be melted is determined. By regulating the temperature itcan be attained that the molten sugar flows out from gap b, e.g., with abright amber-colored transparent color tone.

It is also possible to keep the flowing material by suitable meansfurther on the endless band 11 at a predeter mined temperature, in orderto thus influence its color, if desired. After the desired color tone isattained the material is preferably cooled and solidified in a coolingdevice. In this manner a very homogeneously solidified sugar film isobtained which can be processed in a mill or other suitable device tosugar chips or powder.

The molten sugar film canbe fed in a chute, the inclination of whichrelative to the horizontal direction can be adjusted and which ends in around mouthpiece or nozzle. By the inclination of the chute the durationof stay of the molten sugar in the chute is regulated, so that anydesired color tone, e.g. dark brown, can be attained.

In FIG. 2, drop-formation of the molten sugar is attained at the outletof gap b. For this purpose, the gap is provided with arc-shaped recesses12. In this manner the material flows in the form of drops 13 onto thesurface of a drum 14, which may be cooled, and solidifies in the form ofdrops there. By means of a member 15 the solidified droplets are wipedoff from the drum 14 and deflected to a storage container 16.

In order to increase the melting capacity, several gaps a can be formedby joining together heated plates 1, 2', and 17, 18, as illustrated inFIG. 3.

Furthermore, crystalline sugar can be melted in the form of strands, asshown by way of example in FIG. 4. The heater is here formed e.g. as around body 19, in which bores are provided for the passage of the moltensugar, and said bores end in outlet nozzles 21. Heating of the roundbody 19 can be effected in this case too with electrical heating rodswhich may be introduced into bores 20.

Melting is carried out also in this case in the manner described above.through a funnel 22. Of course, individual strands can be provided sideby side and used for forming strand shaped coatings on pastry, as shownin FIG. 5. Thereby, the pastry 23 is passed in a continuous movementunder the flowing sugar strands 24.

It will be understood that this invention is not limited to the specificsteps, conditions, designs and other details specifically describedabove and can be carried out with various modifications. The startingmaterial is substantially pure, undissolved sugar which is molten bypassing it continuously in a thin layer through the gapformed by tworegistering heated plates, or the like, which are placed at a distanceof about 1 to 4 mm. from each other, or through a tubular opening, orthe like. In order to bring about melting of the sugar the surfaces ofsaid plates or tubular openings must have a temperature in the range of200 to 450 C. Cooling of the molten sugar can be carried out in anysuitable manner. including chilling by contact with an, e.g. metallicsurface cooled to about 20 to C. If desired, the sugar can be kept aftermelting at an increased temperature, e.g., 200

The crystalline sugar is preferably fed It is possible to increase thewidth of gap for instance.

up to 3 mm. to gain a greater output. of molten product. To avoidunmolten material passing the gap it is possible to increase the lengthof gap a or to increase the temperature of the heated plates.

The temperature of the'heated plates however must not be too high sincetoo high'temperatures cause overheating of parts of the sugar. Thereforeincrease of the width of the gap normally calls for increase of thelength of the gap.

What is claimed is:

1. A method of caramelizing substantially pure, solid, undissolved sugarby heating, comprising providing a narrow, generally downwardly,oriented passageway defined by .heatable surfaces, heating the heatablesurfaces to a temperature sufficient to melt the sugar, causing a continuous gravitational flow of solid sugar through said passageway incontact with said heatable surfaces at said temperature over sufficientheatable surface area and for.

a sufficient period of time to cause melting and caramelizing of thesugar.

2. A method of caramelizing sugar as claimedin claim 1 in which themolten sugar is cooled after. caramelizatron.

3. A method of caramelizing sugar as claimed in claim 1 in which thesugar after melting is kept at an increased temperature for a limitedtime and then cooled.

References Cited by the Examiner UNITED STATES PATENTS MORRIS O. WOLK,Primary Examiner.

1. A METHOD OF CARAMELIZING SUBSTANTIALLY PURE, SOLID, UNDISSOLVED SUGARBY HEATING, COMPRISING PROVIDING A NARROW, GENERALLY DOWNWARDLY ORIENTEDPASSAGEWAY DEFINED BY HEATABLE SURFACES, HEATING THE HEATABLE SURFACESTO A TEMPERATURE SUFFICIENT TO MELT THE SUGAR, CAUSING A CONTINUOUSGRAVITATIONAL FLOW OF SOLID SUGAR THROUGH SAID PASSAGEWAY IN CONTACTWITH SAID HEATABLE SURFACES AT SAID TEMPERATURE OVER SUFFICIENT HEATABLESURFACE AREA AND FOR A SUFFICIENT PERIOD OF TIME TO CAUSE MELTING ANDCARAMELIZING OF THE SUGAR.